Does Preferential Hiring Compromise Merit?
- No, almost surely not in this population.
Abstract
Managers fear that the preferential hiring of military veterans leads to the selection of employees who score worse on merit criteria. Using all non-classified records in the U.S. federal government’s Central Personnel Data File from 1973-1997, we compare the educational backgrounds of employees who received veterans’ preference benefits with the educational backgrounds of employees who did not receive veterans’ preference.
Details
The design:
- eliminates uncertainty due to sampling variation, given that we have the population of unclassified data.
- focuses us on the uncertainty surrounding which employees to compare in our analysis.
We replicate prior evidence and media accounts that preference beneficiaries possess weaker educational credentials than non-recipients.
Then we make this relationship disappear—and, in some instances, invert—when we account for employees’ occupations and work circumstances using exact stratification.
Takeaway: The assessment of perceptions of hiring quality requires careful attention to the appropriate basis for comparing employees.
What is Veterans’ Preference?
van Riper’s History of the United States Civil Service notes it is one of the oldest personnel policies in the federal government.
Veterans’ preference predates the competitive civil service exam according to the Merit Systems Protection Board.
Lewis (2012): Under the policy, eligible military veterans—as well as the spouses and mothers of veterans who were disabled or killed in combat—receive either added points on their federal service applications or hiring priority over candidates categorized in the same quality tier.
The Latter Claim is Dubious
Elsewhere, Johnson and Walker (2018) uses pay grade and pay increase data to show equivalent advancement tendencies for preference recipients and non-recipients when entry positions are rendered comparable.
The Data
Unlike the 1% samples, in the summer of 2009, the National Archives and Records Administration (NARA) released a copy of the U.S. Office of Personnel Management’s (OPM) Central Personnel Data File (CPDF) under a FOIA filed by Tim Johnson. This copy of the CPDF contained all non-sensitive employee records from 1973 to 1997. The data are a person-year panel with 3.7 million individual persons.
The Empirics of Veterans’ Preference and Education
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Table
A Graphical View
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Figure 1
Interpretation
- dark grey bar represents the proportion of the category shared by both recipients and non-recipients.
- black bars extending above the dark grey bars represent the proportion of non-recipients within the category in excess of the proportion of preference recipients.
- white bars represent the degree to which a higher proportion of preference recipients reside within the category.
- Education is increasing, left to right, e.g. more black bars on the right-hand side of the diagram means a higher percent of non-recipients possess greater levels of education.
Statistical tests
- Means: Common but not technically correct: two-sample t-tests [Welch]
- Medians: Wilcoxon rank-sum/Mann-Whitney U [coin::wilcox_test]
The Conventional Wisdom
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Table 2
- Enormous t-statistics/Wilcoxon z-statistics.
- Preference recipients have lower levels of education.
The Critical Issue: Whom to Compare?
- Preference recipients are not altogether common.
- It is quite likely that they are not randomly distributed through jobs in the federal service.
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Table 1 Excerpt
The Counterfactual of Interest
- Key argument: the job is a hidden confounder.
- We are fortunate to have measures of five key characteristics of jobs.
- Year of entry: the year the employee entered federal service
- Duty station: where they are employed
- Agency: the agency that employs them
- Occupation: 1519 categories of work
- Grade: GS grades are most common but there are others.
The Precise Question
Our counterfactual of interest, defined by the job as opposed to the person, is, ``had veterans’ preference not played a role in installing the job’s incumbent, how would educational attainment differ for the holder of that job?’’
Jobs as Years of Entry
With caveats, when we retain all data, the conventional wisdom mostly holds though 10 point preference recipients are much higher in 1979 and 1980.
But… year doesn’t seem like the best descriptor of a job.
Jobs as Occupations
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Wilcoxon statistics for Occupations
Jobs as Occupations: Clerk/Assistant [303]
![Evidence]()
The top two results have switched signs: 5-point and 10-point Veterans’ Preference recipients have higher levels of education; the evidence for spouse/mother is a bit mixed.
Education for Clerk/Assistant [303]
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Education by Preference Status for Clerk
Note the abundance of white on the right side of the figures. Higher education levels for preference recipients.
A Job as Year of Entry, Grade, Occupation, Duty Station, Agency
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Most stringent job and education
We still retain lots of comparable data
Notes: The y-axis is censored at 200. The result from this is the top row of the next table.
All Definitions of Jobs
- Grey and black cells contain greater than 20% with p-values less than 0.05.
- Italics and bold represent p<0.05 in the omnibus column.
Discussion
Prior evidence has led to what Pearl (2012, 176) calls a distorted causal interpretation. The broad universal association is quite different than the conditional associations when the job becomes the counterfactual. Though it is claimed that any deviations from merit screening permit less-qualified individuals to enter the federal service, merit screening is only one of many filters.
On balance, we find very little evidence that veterans’ preference worsens the educational attainment of job incumbents.
How could we account for the finding that veterans receiving preference appear to possess equal or greater education in many cases? The GI Bill comes to mind.
Ala Pearl’s discussion of Simpson’s Paradox, given that veterans’ preference accrues to veterans that have access to educational benefits, it is quite easy to see how a relationship in the aggregate showing lower levels of education among preference recipients should fail to replicate for at least some jobs if veterans distribute themselves across occupations differently than nonveterans and veteran status correlates with potential educational benefits.
Punchline
A DEI policy that has no discernible impacts on key elements of expected job performance. Combined with evidence about career trajectories, the belief that DEI policies lead to less qualified candidates is, in this case, quite mistaken.
There is little evidence, given reasonable definitions of a job, that incumbents with veterans’ preference had lower educational attainment than those without preference; the reverse is more plausible.
The top two results have switched signs: 5-point and 10-point Veterans’ Preference recipients have higher levels of education; the evidence for spouse/mother is a bit mixed.
